[diffeomorphism]

The apple pricing ladder is all about the confusingly named overlap.

The Air with more ram costs just a bit less than the pro non-pro. But then maybe you want the pro pro? Or do you need the pro max? Oh, and the ultra will come later but not for laptops. Also it will then be a smaller number M but ultra.

Oh, and the iPad air is, of course, heavier than the pro because "air".